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Brake Woe's and Problem's

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ynotme2

Senior Member
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Hey Everyone,

So here is the newest issue. I got the car out of storage 3 weeks ago. A fabulous spring day and went for a drive. The car was great. I parked it in the garage and then went out for another drive 3 weeks later. The break pedal went all the way to the ground. Almost sponge like. I pulled the reservoir cap and noticed the fluid was about half full. I then looked under the car and it looked like it leaked all over near the fron of the car. I am planning on ripping apart this weekend. Is this probably a master cylinder issue? I don't have a brake servo on the car. I had the front brakes done last year and the mtech said "oh we didn't do anything on the master cylinder" but they rebuilt the front brakes. I hate to tow back to the garage. Another 100.00 bill out the window.

Thanks

Tony
 
First thing to do is determine where the leak is coming from. Is it by the front wheel(s), under the reservoir, by the master cylinder, under the brake light switch, etc? Jack the car up, place on jack stands, remove the wheels, and have someone push on the brake pedal, while you try to find the leak. That will help you decide your next step. It is always possible that it is something simple, like a bleed screw not completely closed or a hose that is not tight or even frayed. What did your brake job include last year? Just new pads? Did they rebuild the calipers? With new pistons? The pistons tend to rust and pit and may need replacing. If the calipers are pitted, they may need to be sleeved? Master cylinders are about $170 if it needs replacing. Pistons, 2 per caliper, are about $30 each. Get stainless steel if you need to replace them.
 
Start looking from the wheel back to the Master cylinder. Check the fittings, connections and hoses. You will probably find a leak somewhere there. I recently had a leaking brake hose (flex) on the front. I have had this happen on rubber hoses (tire contact creating wear of the hose sidewall) and a Stainless Steel hose (leak at the swedged fitting - most unusual). Have someone sit in the car and push on the brake pedal while you observe the area where you are seeing the fluid. Be sure to keep the brake reservior full.

GregJ
 
[ QUOTE ]
If the calipers are pitted, they may need to be sleeved?

[/ QUOTE ]

The calipers usually don't need to be resleeved because the pistons ride on large seals. The original chrome plated pistons do get pitted easily and replacing with Stainless steel is recommended (as you mention!) I purchased some from John Farrell Auto Parts recently. I also got a caliper rebuild kit and special square o-rings used if you split the calipers.

https://www.fortunecity.com/silverstone/tread/1046/id23.htm

The master cylinders and wheel cylinders can be resleeved. On the west coast a good outfit is Sierra Specialty Automotive and it costs about $50 ea. to resleeve in brass https://www.brakecylinder.com/

Cheers,
John
 
Tony,

I just went through a master cylinder problem myself. I ended up rebuilding it with a kit from Moss. If that is your problem, the job is not too bad and the kit is cheap. I had the same pool of fluid but it's hard to localize if it the master. Generally the pool is under the pedal box but you can also go inside the car and lift up the master's rubber boot cover and see if you have a leak at that seal.Mine was oozing fluid from there when I pressed on the pedal.
Be careful to catch any fluid with a rag as that stuff will act as a solvent on paint!
Hope that helps...
 
Recently rebuilt the brake system on my BJ8. Started with a wheel cylinder that was leaking. Replaced all the flex hoses, etc. Everything was fine except a week later I had the same symptoms you describe. Crawled under the steering wheel and pressed the brake pedal by hand while observing the master cylinder and immediately saw fluid....Replaced master cylinder. So far so good. If I were to do it again I would send off the original cylinder for rebuild with sleeve installed. On a side note I also replaced clutch hydraulics including master cylinder. Had a gremlin and it took "forever" for the threads to catch on the reassembly of the fluid lines to the brake cylinder! Be careful if it is an aluminum cylinder to not strip threads out! Good luck.
 
I meant to add that I also replaced the standard bleed fittings with the new type that has a stop valve built in. Got them at Advance Auto. With these bleeders you don't have to open/close them with every stroke of the pedal. Makes it much easier and is REALLY, REALLY nice for the clutch slave cylinder as it is so darn hard to get to!!! That is why I went with them in the first place - made it a much quicker job. Also, be sure to tighten them back up when done (Seems pretty obvious, huh? Don't ask me why I mention that....).
 
One more thing: As the flex hoses are really old unless they have been replaced I recommend you replace them. However, you will easily overlook the flex hose at the split where the rear break lines separate from the main line. This one "imploded" on mine and I discovered it when attempting to bleed. No pressure ..... Flex line looked good on the outside... It, of course, is a little difficult to get a wrench on but the shorties came in handy. That particular flex hose probably had never been replaced in my car as I overlooked it when I last did the brake system fifteen years or so ago...
 
Well I did as you requested and went into the car and applied pressure to the brake pedal by hand. I got a hissing sounds like there was a leak. No fluid came into the car but there was a sound coming from the pushing. Could it be my master cylinder that needs to be rebuilt?

Thanks

Tony
 
YNM2, You have to locate the point of the leakage as Shorn pointed out earlier,use his guidance to locate the leaking item.---Keoke /ubbthreads/images/graemlins/yesnod.gif
 
Tony, I hate to even make this input because it could come off as condescending. Don't mean to be - honest! However, you have refilled the reservoir when checking for the leak, right? Gotta have fluid in the system for it to leak out. I bet you did, but I had to mention it. Mine leaked inside the car and was pretty obvious. I suppose it could leak and go outside the firewall...in that case you might need to be under the car while someone else presses the pedal. The fluid has to be going somewhere....
 
Stever,

No don't worry about any comment you make to me. I am learning as I go and sometimes the small things are what I miss in the hurry for the bigger picture. I never take any commment that way. Just trying to learn. I did indeed refill the reservoir. I will have to have somebody pump the pedal this saturday and I will take a look for the leak. Thanks for all the input. By the way, what is the level on I should fill the reservoir to anyways? Is there a mark in the inside or outside?

I have a stupid question on jacking the car. I understand the best place to jack in the front is under the spring's. If I jack one side up and put it on a jack stand does the fact I am jacking up on one side ever twist the frame out of shape? Just a question thinking about raising the left side of the car on a jack stand before I raise the right side. Does it twist and do damage to the frame. I wouldn't think so but asking just the same.
 
I had a similar problem which just required the kit for the master cylinder.

Did you check your carpet for oil. If is a black carpet you might not have noticed it. Thats where a lot of mine ended up (unfortunatley as it was a new Heritage carpet!)
 
If your resevoir is down,the system may now be empty, top it up and try a quick bleed all round then try your pedal pushing again, with luck, the fluid will come out and your leak is found. If it is the master cylinder it is an easy job to re rubber, especially if you have the manual to hand. The hardest part for me was trying to get the clevis pin back in (pedal to push rod connection) it is right out of the way under the bulkhead.

Bob /ubbthreads/images/graemlins/england.gif /ubbthreads/images/graemlins/cheers.gif
 
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